Macro Examination

Macroscopic examination (macro examination) involves preparing, polishing and etching a weld cross-section to reveal the weld macro-structure for visual assessment under low-power magnification. It is a core destructive test in welding procedure qualification, production quality verification and failure investigation.

QMS Asset Integrity performs macro examination at our Largs North laboratory, covering all major welding codes including AS/NZS 2205.5.1, ASME IX QW-183/184, ISO 17639, and AWS D1.1/D1.2/D1.6. Macro examination is frequently combined with our hardness testing service, allowing a Vickers hardness traverse to be performed on the same prepared cross-section.

A weld cross-section is cut from the test piece at the specified location, mounted if required, and progressively ground and polished to a fine surface finish. The prepared face is then chemically etched (typically with nital for carbon steels or electrolytic etching for stainless steels) to reveal the weld macro-structure.

The etched cross-section is examined under low-power magnification (typically up to 10x) and assessed for: weld geometry and profile, root and cap reinforcement, depth of penetration and fusion, heat-affected zone extent, number of passes, and the presence of defects such as porosity, slag inclusions, lack of fusion, lack of penetration, cracks and undercut.

Results are photographed and documented in a formal test report against the applicable acceptance criteria.